Replies

1. GBA Editor
   Martin Holladay | May 19, 2010 09:20am | #1

   John,
   1. The homeowner should not expect to run every modern gadget, as if the home were grid-connected. All kinds of compromises are necessary. I live without a freezer, dishwasher, toaster, air conditioner, or hair dryer. If the client expects all these things, they better have a very fat budget.

   2. My battery system (six 2-volt forklift batteries for a 12-volt system) cost about $1,600. I expect it to last 6 years -- a few more if I'm lucky. If the homeowner expects gadgets, the cost of the battery system can easily be 4 or 6 times what I paid. They will still wear out in 6 years.

   3. You have to check the water level regularly in all of the battery cells. A bigger battery bank means more water-filling chores -- a pain in the rear. Being satisfied with a smaller battery bank means easier maintenance.

   4. Almost every off-grid home needs a gasoline-powered (or propane-powered) generator for stretches of cloudy weather and winter days.

   5. Can Texans live without air conditioning?

   6. One obvious trick is to fuel as many appliances as possible with propane, including the kitchen stove and the refrigerator.

   7. Don't fall into the trap of specifying a heating system that requires electricity to run, or you'll be screwed. Stick to Empire propane-fired space heaters with through-the-wall vents. They don't require any electricity. A furnace with a blower or a boiler with circulators? Fuggettaboutit.

2. 
   homedesign | May 19, 2010 09:40am | #2

   Martin,
   Exactly the kind of comments that I am looking for.
   I will share this with the homeowner and the builder.
   thanks

3. 
   Daniel Ernst | May 19, 2010 04:35pm | #3

   John,

   Water is another consideration (doubt I need to tell that to a Texan, but . . )

   Are you planning on rainwater collection?

   A friend of mine has an off-grid home. His well pump is connected to a dedicated PV panel. He uses a low amp submersible to pump the water into a cistern, then uses gravity to provide pressure. You would need a substantial head (height) to accomplish the same thing (I think it's around 0.44 lb/ ft. of head). I'm not familiar enough with North Texas to know if that's possible . . .

   You can still pump into a holding tank, then use a secondary low amp surface pump to provide pressure. If you go this route, you might also want to use a large pressure tank - 25 gallon.

   Just a thought. Separating the well pump from the battery pack is another incremental step in reducing your load anyway.

   Martin - How do you manage your water supply?

4. GBA Editor
   Martin Holladay | May 19, 2010 04:45pm | #4

   Daniel,
   In Vermont we have hills. I have a spring above my house that provides gravity-fed water without any electricity.

5. 
   Danny Kelly | May 19, 2010 06:36pm | #5

   Try the NC State Solar Center

   http://www.ncsc.ncsu.edu/

   http://www.ncsc.ncsu.edu/include/_upload/media/pubs/PVSolarHouse.pdf

6. 
   Riversong | May 20, 2010 06:21pm | #6

   John,

   I hate to say it (actually I love to say this), but the first step in going off-grid is reducing one's shelter needs to a minimum. A 3,000 SF home is anything but that.

7. 
   homedesign | May 20, 2010 08:26pm | #7

   Robert,
   You are correct.
   I was thinking the same thing.

8. 
   Paul Scheckel | Jan 05, 2011 12:00pm | #8

   After 20 years of living off-grid, I can advise that its not just about technology, its a lifestyle choice. Awareness is everything. What's the weather going to be? Plan your water pumping, and other high energy draws around the sun, or around running your generator to maximize its use.
   I use 5kwh/day with all modern conveniences including home office, dishwasher, freezer, microwave, well pump. Max savings is about choosing, managing and controlling energy users in a comitted way.
   Oh, and don't forget the need for good friends or neighbors to check on the batteries and run your generator in the dead of winter when you want to get outta town for a few.